diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f9170983..f5a3eef2 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -46,7 +46,8 @@ jobs:
         if: matrix.pm == 'pnpm'
         uses: pnpm/action-setup@08c4be7e2e672a47d11bd04269e27e5f3e8529cb # v6.0.0
         with:
-          version: latest
+          # Keep an explicit pnpm major because this repo's packageManager is Yarn.
+          version: 10
 
       - name: Setup Yarn (via Corepack)
         if: matrix.pm == 'yarn'
diff --git a/.github/workflows/reusable-test.yml b/.github/workflows/reusable-test.yml
index 8b02f15a..ca3406fa 100644
--- a/.github/workflows/reusable-test.yml
+++ b/.github/workflows/reusable-test.yml
@@ -38,7 +38,8 @@ jobs:
         if: inputs.package-manager == 'pnpm'
         uses: pnpm/action-setup@08c4be7e2e672a47d11bd04269e27e5f3e8529cb # v6.0.0
         with:
-          version: latest
+          # Keep an explicit pnpm major because this repo's packageManager is Yarn.
+          version: 10
 
       - name: Setup Yarn (via Corepack)
         if: inputs.package-manager == 'yarn'